Lateral Flow Immunoassays are used by point-of-care markets for immunological testing. Examples of utilization of immunoassays include cholesterol, cardiac markers, diabetes testing. Recently, and due to some constraining patent issues, many manufacturers of lateral flow assays have invested into R&D to develop multiplexing assays on complex platforms for very specific applications, and to improve the design of current lateral flow substrate to increase reproducibility in the final product.
Following advances in microelectronics, biosensor designs are becoming increasingly complex, and focused on miniaturization. The demand for simultaneous measurement of multiple analytes has stimulated development of high density arrays. As a result of this demand, and the advancing capabilities of patterning technologies, research and development programs aimed at sensor arrays containing multiple biomarkers in devices on the order of a square centimeter are underway. Fabrication of these devices typically requires reagent-dispensing approaches capable of delivering volumes ranging from the low microliters to picoliters. Reductions in volume reduce cost of expensive reagents, increase surface dependant reaction rates, and promote adoption of multiplexed diagnostic devices. Dispensing systems used must be compatible with a wide range of reagent classes, including organic solvents, biological fluids, polymeric solutions, as well as the traditional combination of buffer and enzymes. Systems must be robust enough to produce hundreds of thousands to millions of dispenses with a high level of precision and accuracy. Lastly these systems must function in a production environment using less skilled labor and also subject to rigorous regulatory requirements.
The development of manufactured protein arrays is currently getting a lot of visibility due to the existence of an immense field of applications, including biosensors, diagnostics applications such as serum-based diagnostics, and pharmaceutical target design. The latter typically involves the study of protein targets through protein-protein interactions, enzyme-substrate reactions, receptor-ligand interactions, and drug-target binding. Protein microarrays can also be used to miniaturize and multiplex immunoassays and have performed better than enzyme-linked immunosorbent assays in both sensitivity and quantitative range for use in immunoassays.
Flow Through and Lateral Flow diagnostic devices both use membranes as the active media on which the relative biomarkers are printed and the assay is executed. In the Flowthrough device the reagents and sample flow normal to the membrane while in the Lateral Flow device they flow parallel and within the membrane. Both employ an absorbing pad where in Flow through it sits under the membrane and for Lateral Flow it sits at the end of the membrane flow path. Hence the assembly and development methods are somewhat different.
Dry Chemistry (also known as Dip Stick) refers to a diagnostic format where a test pad is bonded to a support structure such as a plastic strip for ease of handling the test pad for exposure to the test sample and read out. The test pad is impregnated with an analyte which when exposed to a test sample will change color or some other physical property which can easily be seen or measured with a reader. One of the most well known applications of Dry Chemistry technology is that of urine testing.
Transferring materials in the solid state has been a challenge for automation for years. Transfer of solid samples with a wide range of properties has proven even more difficult. To further complicate matters, many experiments require sample mass in the microgram range. BioDot's Dispo solid transfer technology provides the ideal solution to these challenges. By coupling a pneumatically actuated z-axis with a cylindrical probe containing a motorized plunger, which is adjusted according to the desired mass, precise amounts of an array of powder types can be aliquoted. The pneumatic action sends the probe down into the source powder, compacting it into the cavity of the probe. With air pressure as the probe's driving force, the amount transferred will remain equivalent even as the source progressively decreases to minimal levels. To dispense, the plunger is lowered down the shaft, thus displacing the powder into a target vial or tray. Air pressure, probe size, and transfer mechanism may be optimized accordingly based on a compound's specific properties.
BioDot offers a unique solid transfer approach with it DisPo series of platforms. To both aid in application development with the automated DisPo platforms as well as for general laboratory solid transfer applications, BioDot has developed the DisPo Handheld series of solid dispensers. These handheld solid dispensers operate much like a conventional liquid pipetter with the noted exception that they deliver solid material. Any application where repetitive or frequent manual weighing of solid material occurs is an ideal candidate for the DisPo Handheld dispensers.
The laboratory manual pipetting market is currently dominated by air displacement handheld mechanical pipettors. However, air displacement pipettes are relatively poor at both accurately and precisely displacing sub-microliter volumes as well as poor at delivering these volumes to their targets. For most applications of sub-microliter dispensing with an air displacement pipettor, “touchoff” contact dispensing is the only means of delivery.
Immunoblotting (alternatively, Western blot, line-ELISA, dot-blot or cold-blot) is an analytical technique used to detect specific proteins in a patients’ sample. The proteins to be analyzed are dispensed onto a membrane (typically nitrocellulose, nylon or PVDF), where they are probed by the antibodies of the patient. A simple secondary antibody conjugated to a reporter dye forms the basis of the color reaction which can be read by eye (qualitative) or instrument (qualitative and quantitative).
A methodology of testing or analyzing within a simulated or organic environment for purposes of biomedical research.
From a biomedical point of view, Point-of-care (POC) can be described as testing or analysis at the site where a simulated environment (and sometimes not simulated but organic. I.E, a patient suffering from a disease) is utilized to conduct research on a given task or problem. Point of care is conducted through the implementation of several specialized instruments and testing equipment (i.e. biosensors, immunoblotters, syringes, petri dishes, heartbeat sensors and other devices).
The principle purpose behind POC is to conveniently and simultaneously test all aspect of the given task, in essence, speeding up the solution. This process will significantly raise the probability of the solution being an accurate one. Scientists and research/development teams will receive the results quicker, which allows for immediate technical management decisions to be made. Some aspects of point of care include: RT-qCPR analysis, MRI analysis, Glucose analysis, urinalysis, blood test, bacterial screening, pathogen screening, drug screening, chemical excretion screening, salivary assay, FSH-LSH testing and analysis, HPTA analysis, endocrine function analysis, and many other procedures.
Small bench analyzers or fixed equipment can also be used when a handheld device is not available--the goal is to collect the specimen and obtain the results in a very short period of time at, or near the location of the problem, so that the treatment plan can be adjusted as necessary before any other variables come into play. Cheaper, smaller, faster, and more advanced POC devices have increased the use of POC approaches by making it cost-effective for many diseases, such as malaria, rheumatoid arthritis and human immunodeficiency virus. Point of care is affected by several factors, here are some important ones:
- Proper POC instrument implementation according to circumstance.
- Usage of POC equipment that implements a high level of technology and practicality.
- Benefits that the POC equipment offers with proper use.